December 6, 2010
Try to schedule your screening mammogram during the first week of your menstrual cycle. It might make breast cancer screening more accurate for pre-menopausal women who choose to have regular mammograms. This recommendation comes from an article published online December 3 in Radiology by Diana Miglioretti, PhD, a senior investigator at Group Health Research Institute.
Dr. Miglioretti and her co-authors are working on an issue at the heart of recent controversies about breast cancer screening mammograms. In November 2009, new recommendations—including that women should discuss with their doctors whether to begin having regular screening mammograms at age 40 or wait till age 50—were issued by the U.S. Preventive Services Task Force, an independent panel of health care providers who generate medical guidelines based on clinical research.
Some facts related to the new recommendations prompted the study by Dr. Miglioretti and colleagues:
- Mammography can detect cancer in women in their 40s.
- But these women are at higher risk than are older women for a false-negative result (missing a cancer that is present) or a false-positive result (recalling a woman for further workup when cancer is not present).
- False positives lead to unnecessary tests, including biopsies.
- Women in their 40s tend to have dense breast tissue, making their mammograms hard to interpret. Dense breast tissue shows up as white on a mammogram and can obscure abnormal findings, which are also white.
- Breast density varies slightly with menstrual cycle.
Dr. Miglioretti’s team asked whether mammography conducted at different times in the menstrual cycle, when breast density may be different, is more sensitive for finding breast cancers or more specific for ruling out cancer. They examined 387,218 screening mammograms from premenopausal women. Of these, 1,283 were linked to an actual case of breast cancer. The data were from the Breast Cancer Surveillance Consortium, a network of research sites nationwide—including Group Health Research Institute, which has collected breast cancer screening data since 1994.